草地开垦人为加速侵蚀的人工降雨试验研究

通过野外人工降雨试验分析了人为破坏草被对土壤加速侵蚀的影响。研究结果表明天然草地基本上不发生径流和土壤流失。天然草被破坏开垦后径流量增加1273～3050m³/km²，产沙量增加500～1700t/km²。撂荒地（4年）的径流量明显高于天然草地，但土壤侵蚀量很小，撂荒地开垦后径流和流失量明显高于天然草地开垦后的径流量和侵蚀量，其中产沙量为新开垦天然草地的6.2倍。草地的地上部分吸水量占降雨量的15.5%，天然草地上地形、降雨因子对土壤侵蚀的影响甚微。草地开垦后，土壤侵蚀量随雨强和坡度的增加而增大。

Study on Man-made Accelerated Erosion of Grassland Being Reclaimed by Simulated Rainfall Experiment

Effect of grass vegetation destroyed by human on man-made accelerated erosion pro-tess has been analysed in this paper,using simulated rainfall experiement,The results show that after grass land being destroyed and reclaimed,runoff yield increases 1273～3050m³/km²,sedi-ment yield is 500～1700t/km²,at single rainfall condition.Soil erosion intensity on the wasteland (wasteland after 4 years)is slight,but the wasteland being cultivated,runoff yield and soil loss is much bigger than those in the grass land being cultivated,and sediment yield is 6.2 times than that of grass land being cultivated.The interception rainfall of leaf and stalk parts is 6.9mm,it occupies 15.5% of rainfall amount.Impact of topography and rainfall on soil erosion is not obvious in grass land,but after grass land being cultivated,soil loss increases with increase of rainfall intensity and slope degree.